Biomass burning (BB) has a significant influence on the Arctic environment. Here, we determined the atmospheric levels of BB-specific tracer compounds such as levoglucosan (Lev), galactosan (Gan), and mannosan (Man) in Arctic aerosols during 2010-2018. The average concentrations of Lev during the study period ranged between 0.43 and 4.15 ng m(-3). Both Lev/Man (0-30) and Man/Gan (0-3) ratios further suggested their origin from softwood/hardwood burning. The North Atlantic Oscillation (NAO) was the main driver of the Lev variability during the study period and Lev could be advected to Arctic air during the NAO was in a positive phase. Based upon the levels of Lev, black carbon (BC) generated from BB was estimated, and the corresponding radiative forcing was then calculated by Santa Barbara DISORT Atmospheric Radiative Transfer. BC has a potential warming effect in the atmosphere (+4.28 W/m(2)) while shows a cooling effect on the surface, which is equivalent to a large volcanic eruption (-3 W/m(2)). Since climate change is expected to intensify BB around the Arctic, such BC aerosols should be considered in future climate model projections.

A study of electronic states of LiO, NaO, KO, MgO, and CaO molecules has been performed. Potential energy curves of the investigated molecules have been constructed within the framework of the XMC-QDPT2 method. Lifetimes and efficiencies of photolysis mechanisms of these monoxides have been estimated within the framework of an analytical model of photolysis. The results obtained show that oxides of the considered elements in the exospheres of the Moon and Mercury are destroyed by solar photons during the first ballistic flight.